Object tracking method and apparatus using template matching

Abstract

An object is detected in comparison between an input image from an image pick-up device having a zoom mechanism and a template image stored in a manner that a first image within a view field of the image pick-up device is stored as a first as the template image, a power of the zoom mechanism to be changed is recorded, a second image to be detected is picked-up from the image pick-up device. Then, a size of either one of the template image and the second image is changed on the bases of the changed power of the zoom mechanism, and a template matching is performed between the template image and the second image to detect the object. This process makes it possible to track an object within the view field.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]The present invention is related to U.S. patent application Ser. No. 09 / 592,996 filed Jun. 13, 2000 entitled “OBJECT TRACKING METHOD AND OBJECT TRACKING APPARATUS”BACKGROUND OF THE INVENTION[0002]The present invention relates to a monitor apparatus using an image pickup unit, or in particular to an object tracking method for automatically detecting an object intruding into an imaging field or image pickup field from a video signal inputted from the image pickup unit and automatically tracking the motion of the detected object and an object tracking apparatus for automatically adjusting the imaging direction (central direction of an image) in accordance with the detected motion of the object.[0003]A video monitor apparatus using an image pickup unit such as a television camera (referred to as a TV camera) has been widely used. As one of the monitor systems using such video monitor apparatuses, a manned monitoring system may be referred in w...

AI Technical Summary

Benefits of technology

[0033]The change of a zooming ratio of the image pickup unit makes the intruding object displayed on the template image different in size from the intruding object to be detected on the input image, thereby causing the degree of coincidence to be lower. As a disadvantage, therefore, if the degree of coincidence is not more than the predetermined value, the disability to detect the intruding object is determined.

[0036]It is another object of the present invention to provide an object tracking method and apparatus which are arranged to precisely detect and track an object with high reliability.

[0044]However, as described above, according to the present invention, the zooming ratio is calculated with reference to the ratio of a focal distance (focal length) at the time of obtaining the template image to a focal distance at the time of obtaining the input image and thereby the template image is magnified according to the zooming ratio. This allows a target intruding object to be precisely tracked as controlling or operating the zoom lens.

[0045]The present invention, therefore, provides a capability of eliminating the conventional restriction of the zoom lens control of the image pickup unit, reliably tracking the intruding object, and greatly spreading the application range of the video monitor apparatus.

Problems solved by technology

Hence, the change of a zooming ratio (zooming power) of the image pickup unit makes the intruding object displayed on the template image different in size from the intruding object to be detected in the input image, which brings about a disadvantage that no precise positioning of the intruding object can be performed.

As a disadvantage, therefore, if the degree of coincidence is not more than the predetermined value, the disability to detect the intruding object is determined.

As described above, if the zooming ratio (zooming power) of the zoom lens undergoes a change, as a disadvantage, the object tracing method using the foregoing template matching of the prior art provides no capability of precisely detecting the position of the intruding object and further detecting the intruding object itself.

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